Parallel pathways in visual cortex: functional connectivity of output pathways fr

项目摘要 理解大脑皮层神经回路的组织原理对于理解大脑皮层神经回路的功能是必要的。 计算函数这一原理为致力于生成 大脑的线路图，或者说是不同比例的大脑分区。 在灵长类动物的视觉皮层中，V1和V2区将它们从视网膜接收到的信息分配给几乎所有的神经元。 更高的区域，将这些信息分为背侧和腹侧处理流，用于空间和物体视觉， 分别这个应用程序的目的是揭示解剖和功能连接的规则 V1和V2输出通路，以了解这些区域如何改善和重新组织视网膜 信号转化为视觉处理流，以及这些途径如何有助于创造复杂的感受性 场（RF）特性的神经元在更高的地区。从V1到V2的平行通路投射到不同的 细胞色素氧化酶条纹（厚，薄和苍白）。在上一个赠款期间，我们发现了4个 V1和V2之间的分离途径。我们还发现了V1的专门功能组织 与厚条纹和浅条纹相关的通路，可能是V2 RF对成角和弯曲的响应的基础 轮廓本建议以这些调查结果为基础。目标1的目标是了解单个V1细胞如何 通过确定单个V1输出细胞的轴突和树突布局， V1和V2方向图。我们将提供第一个全面的解剖描述在介观 投射到特定V2条纹的V1细胞规模，包括V1和V2内轴突分支， 已识别的细胞类型及其在V1和V2中的功能组织。这些信息将提供 深入了解前馈与V2内机制在V2 RF生成中的作用，以及 内V1和V1到V2电路对轮廓处理的贡献。然后我们将调查是否 4条通路的解剖学和功能分离在V2下游保持或丧失。的目标 目的2是确定两个V2浅条纹类型的面积投影，我们最近已经 被证明是不同的隔间。这项研究将确定每个苍白条纹的贡献， 背侧和腹侧处理流。V2和V4包含视觉刺激的分离表示 方向和颜色。Aim3的目标是确定V2和V4之间的连接是否发生在 相似特征表示的区域，或者V4中是否发生交叉流会聚。本研究将 还提供了对前馈与区域内机制在V4 RF生成中的作用的见解， 特色地图这项拟议中的研究意义重大，因为它将揭示解剖和功能布线 V1和V2输出路径的原则，将作为假设驱动的基础， 解剖学限制的功能研究。这项研究是创新的，因为它结合了 使用用于单轴突标记的新方法的具有单轴突的高分辨率标记的功能成像 和重建。

PROJECT SUMMARY Understanding organizing principles for neural circuits in the cortex is necessary to understand their computational function. This principle has informed the new field of "connectomics", devoted to generating wiring diagrams of the brain, or subsections of it, at different scales. In the primate visual cortex, areas V1 and V2 distribute information they receive from the retina to virtually all higher areas, sorting this information into dorsal and ventral processing streams for spatial and object vision, respectively. The objective of this application is to uncover the rules of anatomical and functional connectivity for V1 and V2 output pathways, in order to understand how these areas may refine and re-organize retinal signals into visual processing streams, and how these pathways contribute to creating the complex receptive field (RF) properties of neurons in higher areas. Parallel pathways from V1 to V2 project to distinct cytochrome-oxidase stripes (thick, thin and pale). During the previous grant period, we discovered 4 segregated pathways between V1 & V2. We also discovered specialized functional organizations of V1 pathways related to thick and pale stripes that may underlie the responses of V2 RFs to angled and curved contours. This proposal builds upon these findings. The goal of Aim 1 is to understand how single V1 cells contribute to generating V2 RFs, by determining the axonal and dendritic layout of single V1 output cells over the V1 and V2 orientation maps. We will provide the fist comprehensive anatomical description at mesoscopic scale of V1 cells projecting to specific V2 stripes, including the intra-V1 and intra-V2 axonal arborizations of identified cell types, and their functional organization within both V1 & V2. This information will provide insights into the roles of feedforward vs. intra-V2 mechanisms in the generation of V2 RFs, and on the contribution of intra-V1 and V1-to-V2 circuits to the processing of contours. We will then investigate whether anatomical and functional segregation of the 4 pathways is maintained or lost downstream of V2. The goal of Aim2 is to determine the areal projections of the two V2 pale stripe types, which we have recently demonstrated to be distinct compartments. This study will determine each pale stripe contribution to the dorsal and ventral processing streams. V2 and V4 contain segregated representations for visual stimulus orientation and color. The goal of Aim3 is to determine whether connections between V2 & V4 occur between regions of similar featural representation, or whether cross-stream convergence occurs in V4. This study will also provide insights into the roles of feedforward vs. intra-areal mechanisms in the generation of V4 RFs and featural maps. The proposed research is significant because it will reveal anatomical and functional wiring principles for V1 and V2 output pahways that will serve as a foundation for hypothesis-driven and anatomically-constrained studies of their function. The proposed research is innovative because it combines functional imaging with high-resolution labeling of single axons, using novel methods for single axon labeling and reconstruction.